Problem: $ D = \left[\begin{array}{rr}1 & 3 \\ 5 & 4 \\ 3 & 1\end{array}\right]$ What is $ D^{T}$ ?
Explanation: To find the transpose, swap the rows and columns. $ D^{T}$ = $\left[\begin{array}{rrr}1 & 5 & 3 \\ 3 & 4 & 1\end{array}\right]$